Editing Radionuclide (section)

==Uses==
Radionuclides are used in two major ways: either for their radiation alone ([[irradiation]], [[nuclear battery|nuclear batteries]]) or for the combination of chemical properties and their radiation (tracers, biopharmaceuticals).
* In [[biology]], radionuclides of [[carbon]] can serve as [[radioactive tracer]]s because they are chemically very similar to the nonradioactive nuclides, so most chemical, biological, and ecological processes treat them in a nearly identical way. One can then examine the result with a radiation detector, such as a [[Geiger counter]], to determine where the provided atoms were incorporated. For example, one might culture plants in an environment in which the [[carbon dioxide]] contained radioactive carbon; then the parts of the plant that incorporate atmospheric carbon would be radioactive. Radionuclides can be used to monitor processes such as [[DNA replication]] or [[amino acid]] transport.
* in [[physics]] and [[biology]] radionuclide X-ray fluorescence spectrometry is used to determine [[chemical composition]] of the [[Chemical compound|compound]]. [[X-ray|Radiation]] from a radionuclide source hits the sample and excites characteristic X-rays in the sample. This radiation is registered and the chemical composition of the sample can be determined from the analysis of the measured spectrum. By measuring the energy of the characteristic radiation lines, it is possible to determine the [[Atomic number|proton number]] of the [[chemical element]] that emits the radiation, and by measuring the number of emitted [[photon]]s, it is possible to determine the [[concentration]] of individual chemical elements.
* In [[nuclear medicine]], radioisotopes are used for diagnosis, treatment, and research. Radioactive chemical tracers emitting gamma rays or positrons can provide diagnostic information about internal anatomy and the functioning of specific organs, including the [[human brain]].<ref>{{cite journal|last1=Ingvar|first1=David H.|author-link1=:sv:David H. Ingvar|last2=Lassen|first2=Niels A.|author-link2=Niels A. Lassen|title=Quantitative determination of regional cerebral blood-flow in man|journal=[[The Lancet]]|year=1961|volume=278|issue=7206|pages=806–807|url=http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2861%2991092-3/fulltext|doi=10.1016/s0140-6736(61)91092-3}}</ref><ref>{{cite journal|last1=Ingvar|first1=David H.|author1-link=:sv:David H. Ingvar|last2=Franzén|first2=Göran|title=Distribution of cerebral activity in chronic schizophrenia|journal=[[The Lancet]]|year=1974|volume=304|issue=7895|pages=1484–1486|url=http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2874%2990221-9/abstract|doi=10.1016/s0140-6736(74)90221-9|pmid=4140398}}</ref><ref>{{cite journal|last1=Lassen|first1=Niels A.|author-link1=Niels A. Lassen|last2=Ingvar|first2=David H.|author-link2=:sv:David H. Ingvar|last3=Skinhøj|first3=Erik|author-link3=:da:Erik Skinhøj|title=Brain Function and Blood Flow| journal=[[Scientific American]]|volume=239|issue=4|pages=62–71|date=October 1978|doi=10.1038/scientificamerican1078-62|pmid=705327|bibcode=1978SciAm.239d..62L}}</ref> This is used in some forms of tomography: [[single-photon emission computed tomography]] and [[positron emission tomography]] (PET) scanning and [[Cherenkov luminescence imaging]]. Radioisotopes are also a method of treatment in [[hemopoietic]] forms of tumors; the success for treatment of solid tumors has been limited. More powerful gamma sources [[sterilization (microbiology)|sterilise]] syringes and other medical equipment.
* In [[food preservation]], radiation is used to stop the sprouting of root crops after harvesting, to kill parasites and pests, and to control the ripening of stored fruit and vegetables. [[Food irradiation]] usually uses beta-decaying nuclides with strong gamma emissions like [[cobalt-60]] or [[caesium-137]].
* In [[Industrial sector|industry]], and in [[mining]], radionuclides are used to examine welds, to detect leaks, to study the rate of wear, erosion and corrosion of metals, and for on-stream analysis of a wide range of minerals and fuels.
* In [[spacecraft]], radionuclides are used to provide power and heat, notably through [[radioisotope thermoelectric generator]]s (RTGs) and [[radioisotope heater unit]]s (RHUs).
* In [[astronomy]] and [[physical cosmology|cosmology]], radionuclides play a role in understanding stellar and planetary process.
* In [[particle physics]], radionuclides help discover new physics ([[physics beyond the Standard Model]]) by measuring the energy and momentum of their beta decay products (for example, [[neutrinoless double beta decay]] and the search for [[weakly interacting massive particles]]).<ref>{{cite journal|doi=10.1103/RevModPhys.78.991|title=Tests of the standard electroweak model in nuclear beta decay|journal=Reviews of Modern Physics|volume=78|issue=3|pages=991–1040|year=2006|last1=Severijns|first1=Nathal|last2=Beck|first2=Marcus|last3=Naviliat-Cuncic|first3=Oscar|bibcode=2006RvMP...78..991S|arxiv = nucl-ex/0605029 |s2cid=18494258}}</ref>
* In [[ecology]], radionuclides are used to trace and analyze pollutants, to study the movement of surface water, and to measure water runoffs from rain and snow, as well as the flow rates of streams and rivers.
* In [[geology]], [[archaeology]], and [[paleontology]], natural radionuclides are used to measure ages of rocks, minerals, and fossil materials.<!-- When radioactive carbon, for example, is in the atmosphere, it rapidly becomes separated from its decay products. Once it is bound up in a solid, such as wood or paper, its decay products must remain in place. Therefore, by measuring how much of these decay products have accumulated, one can estimate the time when the carbon was captured into solid form. -->